Control for machine tools



April 1952 J. E. MAKANT El'AL CONTROL FOR MACHINE TOOLS 9 Sheets-Sheet 1Filed Oct. 9, 1947 April 29, 195.2 J. E. MAKANT EIAL CONTROL FOR MACHINETOOLS 9 Sheets-Sheet 2 Filed Oct. 9, 1947 Iiiiii April 29, 1952 J. E.MAKANT ETAL CONTROL FOR MACHINE TOOLS 9 Sheets-Sheet 3 Filed Oct. 9,1947 5 M E fi l l l I I I 1 I l I l I l I I 1 I l l l I I I Iv AT 1 K r1 .1. -flMW- 314 5 0 MMH 50M 4 mME 21 April 29, 1952 J. E. MAKANT ETALCONTROL FOR MACHINE TOOLS 9 Sheets-Sheet 4 Filed Oct. 9, 1947GOROOIVWSMITHSON o KEN/VET April29, 1952 J. E. MAKANT ETAL CONTROL FORMACHINE TOOLS 9 Sheets-Sheet 5 Filed Oct. 9, 1947 WNW April 29, 1952 J.E. MAKANT ETAL CONTROL FOR MACHINE TOOLS 9 Sheets-Sheet 6 Filed Oqt. 9,1947 April 1952 J. E. MAKANT ETAL CONTROL FOR MACHINE TOOLS 9Sheets-Sheet 7 Filed Oct. 9, 1947 J. E. MAKANT EI'AL CONTROL FOR MACHINETOOLS April 29, 1952 9 Sheets-Sheet 8 Filed Oct. 9, 1947 y M Z .M r w MMWOX a WN Wmru 14MW. Msfi w MM $0 G 6 W I WV N 3/ W8 MM w a MM 4 4 mm HmApril 29, 1952 J. E. MAKANT ET AL 2,594,782

CONTROL FOR MACHINE TOOLS Filed Oct. 9, 1947 9 Sheets-Sheet 9 D 1 J J 764 1 1 1 J 1 1 [HUN-[J C 5 :fd FUSE 6 l STOP 6. mm: CONTROL FEED . IFAST/V0770 j /V!U7RAL CONTROL 2 'FAJTMIIT/ON CHANGE FEED CHANGE I JOSEPHE. MAX/1N7, A GOEOON WSM/THSO/V -41 Est-Nam m5 REM) KENA/fTHkWU/VSCHELOPf/Y nvrzewck M CLOSED M'TEEL 06K M 0mm 0/10 RELAY SOLENOID PatentedApr. 29, 1952 UNITED STATES PATENT OFFICE CONTROL FOR MACHINE TOOLSJersey Application October 9, 1947, Serial No. 778,7 74

16 Claims.

possible, variations in the speed of the spindle and in the feed of theturret-slide or carriage or of the cross-slides. Such quick change ofspeed and feeds of machine tools has been proposed in U. S. Patent2,357,396 wherein such variations or changes are accomplished byshifting appropriate clutches by pneumatic pressure which iselectrically controlled.

The present invention has for its object the employment of pneumaticmechanism for shifting the clutches of the spindle speed and of theturret-slide and/or cross-slide feed movements to change the rate ofspeed rotation of the spindle and of the feed movements of said slides,the organization and arrangement of said pneumatic mechanism being suchas to apply its clutch shifting pressures more directly and quickly tothe clutches, thus eliminating many parts in the form of mechanicalconnections and greatly simplifying the same; and, also, to

provide, as a safety feature, a novel and an im-.

proved mechanical interlocking means between the pneumatic mechanism foractuating the change-feed clutches so that only one clutch may beengaged at any one time, the arrangement being that if one feed clutchis actuated to en effect a disengagement of all other change-feedclutches.

Another object of the present invention is the provision, in saidpneumatic clutch shifting means, of a novel control mechanism foralternately engaging and disengaging a main-feed clutch and a constantspeed fast-motion clutch for effecting feed or rapid movements of theturret-slide; or for stopping either of said moveprovision of a novelarrangement for insuring" a binding action of the turret locking meansafter each turret indexing operation.

Also, it is an important object of the invention to provide anelectrical control circuit that controls the operations of theelectro-pneumatic means from a pre-set dog drum synchronously operatedfrom the output side of said clutches or feed-change mechanism of theturret-slide so that the timed relationship between the slide vgage itsclutch, said engaging movement will trical control circuit includinginitiating switches and relays controlling circuits embracing saidinitiating switches insuch a manner that the turret slide may be placedin feeding movement or quick-motion movement alternately, or either ofsaid movements of the slide may be stopped, and, so that when one of theinitiating switches is operated, it takes command of the controlcircuits irrespective of whether a previously operated initiating switchhas been released from its initiating position.

The above broadly states the objects sought to be attained by thepresent invention but other objects and novel features of the inventionwill be apparent as the description of the invention proceeds.

In the drawings which show the preferred embodiment of the invention asapplied to one form of machine tool and as at present devised:

Figure 1 is a perspective view of an automatic turret lathe lookingtoward the front of the machine and equipped with the present invention;

Figure'2 is an end view of the machine looking toward the head-stock andwith the end door removed to show the arrangement and disposition of theshafts and other mechanism disposed within the head-stock;

Figure 3 is an enlarged fragmentary view of the rear of the head-stockwith the door and closure plate removed to illustrate the dispositionand location of certain shafts, gears and clutches; and, particularly,the disposition of the pneumatic mechanism for efiecting change-speedand change-feed;

Figure 4 is a diagrammatic view illustrating the lay-out of the gearingfor driving the spindle and turret slide and the disposition of theclutches for automatically changing the spindle "speed and the feedmovements of the turret slide as well as the electro-pneumatic mechanismfor operating said clutches;

Figure 5 is an enlarged front elevation of the dog drum and theinitiating electrical switches operated thereby or which may be operatedmanually;

Figure 6 is a longitudinal sectional view of the turret slide takensubstantially on line 6--B of Figure 1;

Figure 7 is a plane view of the turret slide taken substantially on line1! of Figure 6;

Figure 8 is a fragmentary schematic showing of the slide tool actuatingmechanism operable from the turret operating cam;

Figure 9 is a fragmentary schematic illustration similar to Figure 8showing the slide tool actuator being operated by the turret operatingcam;

and the dog drum will not be altered, said elec- 3 Figure 10 is anenlarged vertical sectional view of a solenoid airyalve employed inthe-electropneumatic control mechanism;

Figure 11 is an end elevation of the pneumatic mechanism P that operatesthe clutch slide or cone for placing the turret slide inits feedmovements or in fast-moticncr for stopping said movements;

Figure 12 is a transverse sectional view taken substantially on lineI2l2 OfFigure 11 to show details of said pneumatic mechanism P;

Figure 13 is a fragmentary side elevation of one end of the pneumaticmechanism-P not shown in Figure 11;

Figure 14 is an elevation of said end of the pneumaticmechanism:shown inFigure 13; and

Figure :15 is aline diagram of the electrical "control circuits 'of theinvention.

The accompanying drawings above mentioned from, by :reference, "a partof this written de- ;scri ption.

The tyne of machine with which the present invention is illustrated inthe drawings is an automatic turret lathe as shown in United StatesPatent No. 2,455,876, granted December 7, 1948, but wherein the clutchshifting mechanism, as shown in Figures 13 to 21 inclusive of saidpatent, has been replaced by the present invention and, .in addition,several other improvements in the -ma'chine,'shown in said application,have'been made in the turret locking means, and in slidetool operatingmechanism, as will appear as this-specification proceeds. It is to beunder- 1StQ0d,'h0WBV8l, thatthe inventionis not to be limitedto'themachine illustrated and described hereinvbutgmay be appliedtoany othertype of machineto which the invention is applicable.

In orderthat an-understandin'g may be'liad of the machine illustrated inthe drawings and "to which the invention is applied,-asone example,

it should be stated that the machine shown *in 410 '25 at-one end 'ofwhich is a headstockzdhavin ahorizontally disposed spindle 2irrotatablyjour- =nalled therein and 'having disposed therein the power andvariable transmission units of the machine. On the inner end 'of thespindle and overlying the bed 24 is fixedly secured :a chuck 22 in whicha workpiece (not'shown) :may be clamped'inthe usual manner.v:lViounted-on the bed 24 "for reciprocable sliding movementlongitudinally of the'bedandrparallel-to theaxisiof the spindle iltoward and 'awayfrom the chuck "22:on'the spindle 2 I, is :aturret slideor carriage 23; and, also mounted onthe'bed 24 and-disposed between thechuck 22 and the carriage 2-3, are front and rear cross slides 25 and26, respectively, which may be operated independently or simultaneouslyto reciprocate at substantially right angles with respect to movement of,the turret slide or carriage 23 .andjin cooperative relation with aworkpiece that maybe held on the chuck 2-2.

With particular reference to Figures 1, 2, 3 and .4, the headstockincludes an outer casing for power plant motors, transmission mechanism,including its clutches, the electro-pneumatic mechanism for shifting theclutches, the elec--' trical control mechanism, as well as to providebearings 21-and 28 for the spindle 2i and a bearing 29 for the feedshaft 36.

The upper portion of the base 24 provides a "table-like member 2 l uponwhich are mounted worm wheel the speed-output sha'ft. "headstock- 2Bincooperativemlation and parallel tturretslide 23 and .the cross slides25 and 26,

:the mechanism for operating said turret slide, which includes the camdisc I35, shaft 154 and i5l, being disposed respectively above and'belowthe table 2% and being driven ,by the Worm ,tdafast on the feed shaft30.

Thesp'indle if is driven by constant speed motor'M connected by asprocket chain 33 passing over sprocket wheel on the motor shaft and asprocket wheel 235 fast on the rotatable shaft 38.

Headstock Referring particularly to Figure 4 it will be seen'there aretwo axially aligned shafts 33 and 3! mounted in suitable bearings in theheadstock frame 2 9; theshaft 't fi ming-what may be termed,

the speed input shaft and the shaft =3! being Also journalled in the ofany suitable type :although, in the present showing, disc-clutches areillustrated. The sliding parts I or cones 4'3 and t l are i spline'd onthe shaft 38 and are shifted-by suitable yokesras can beseen moreparticularly from'Figure-. *Each of the clutc'h heads 39, 40, El :and-2'have 'fast therewith gears 55, 43, G1 and 48, respectively,

of difierent sizes to--efiect the automatic change speeds desired. The:gears 5 and A3 of clutch heads '38 and 48 :mesh, respectively, withtheir mating gears 69 and it "fast on the speed input shaft 36 while thegears i! and 548 of clutch heads M and 42 mesh :with :their mating gearsBI and 52 fast .on the speed output shaft 31.

'With this arrangement, to obtain the "four automatic change spee'daitheoperation ofrthe clutches is as follows:

1. To obtain the lowest speed of spindlepperation, clutch cone '43engages clutch thead Ml fast on "speed output shaft 31';

2.111 order to obtain the-second speed of spindle operation, clutch conel-3 remains engaged with clutch head idfl'but'cone' 44 disengfigesclutch head 22 and engages clutch head 4|, the drive then being fromspeed input shaft'35 through gears .50, ,dfi shaft 38, gear ,G'l, ,gear5| to speed output shaft 31;

3. To secure the third speed sot spindle operticn, clutch coneJlSengages, clutch head 39 i(thereby disengaging clutch head 4.0) andclutchcone 44 engages clutch head '12, if-not already in engagemerittherewith, whereby the-drive is from input speed shaft 36 through gears49, 45, shaft 38, gears iBtand '52't0 speed outputshaft 31; and

4. .To-obtain -.the fourth and highest :speed of spindle operation, :the:clutch cone 43 :engages in clutch head 39, :if not-already .inengagement therewith, and the clutch cone M is moved in engagement withthe clutch head 41, whereby the drive is from speed input shaft 36,gears 49 therein meshing with a gear 69.

and 45, counter-shaft 88, gears 41, 5| to speed output shaft 31.

From the above it will be observed that, during these four automaticspeed changes, one of each pair of clutch heads with their mating gearsare always engaged while the other two clutch heads with their matinggears run idle on the countershaft 38, and that any combination of twoclutches may be engaged simultaneously within the limitation, of course,that when one clutch of a pair is engaged the other clutch of the samepair is disengaged which is a feature of safety as will appear laterfrom the description of the clutch operation mechanism.

The spindle drive continues from the speed output shaft 31 throughhand-change gears 53 and 54 to shaft 55. These hand-change gears are,respectively, fast on the outer ends of the shafts 31 and 55 so as to beaccessible, as shown in Figure 2, for quick manual change through asuitable door in the end wall of the headstock casing 20 may be providedin groups to obtain different ranges of speeds in a manner and for apurpose well known in the art.

From shaft 55 the machine may be converted from a low speed to a highspeed machine, and conversely, but always influenced by the speedchanges which are effected by the hand-change gears 53 and 54 andthrough the automatic clutches just described. By providing shaft 55with multiple splines 56 on which a double gear 57 and 5! slides and bymoving the double gear 51 and 5l' manually so that either the low speedgear 5'! will mesh with its mating gear 58 or the high speed gear 5l'will mesh with its mating gear 59, such change-over may be effected. Thedouble gear 5T5l may be shifted by a bar 51 slidably mounted in bearingopenings in the headstock frame 20, having a yoke 51 on one end and rackteeth 57 in engagement with a gear 51 faston a shaft 5'! which extendsthrough the front wall of the headstock casing 25 to receive the end ofa socket wrench or crank.

It will be observed that gears 58 and 59 are keyed to a jack-shaft 60and that gear 59 is in mesh with a gear 6! keyed to a sleeve bearing 62in which the rear end of the spindle 2! is splined at 63 forlongitudinal adjustment therein. The sleeve bearing 62 is journaled at28 in the headstock casing 20, as is the shaft 55 and the jack shaft 60,in suitable ball bearings.

The front or chuck end of the spindle 21 is journaled in a bearingsleeve 64, which latter is slidably mounted in a bearing 21 on thecasing 20 for longitudinal movement in order to provide the adjustmentof the spindle 2| longitudinally to or from the slide 23 or a turretface on said slide. This adjustment may be accomplished by the provisionof a pinion 65 journaled on the headstock and engaging a rack 66 on thespindle sleeve 64, the pinion being operated through a shaft 61 having asquared end extending through the headstock casing 25 (see Fig. 1).

Feed shaft drive The drive for the feed shaft 3!! (which actuates theturret slide 23 and cross slides 25 and 25) is connected directly withthe spindle 2! so that the feed will always be in ratio per revolutionof the spindle. This feed drive is taken off of the spindle sleeve 62,which has teeth 68 cut The gear 69 is keyed to a jack shaft which has aspur gear 69 fast thereto for driving gear 'H keyed to one end of a stubshaft (2 which also has gear 6 13 fast thereon to drive gear 15, throughthe intermediate gear 14. The gear 15 is keyed to an input speed shafti5 which is aligned with and rotatably independent of an output speedshaft 11 for the feeding movements to the turretslide 23 and thecross-slides 25 and 26.

From this input shaft 16, various feed changes may be obtained throughthe medium of handchange gears for the tool slides as well as threeautomatic feed changes of any selected feed obtained by the hand-changegears. As shown in Figures 2 and 4, three separate and independentcountershafts 18, 19 and are grouped about the aligned input and outputshafts l6 and H and suitably journaled in the housing 20. Each of thesecountershafts 18, 19 and has rotatably mounted thereon a clutch head 8!,83 and 85, respectively, each clutch head having a mating gear 82, 84and 86 fast thereon, respectively, which gears are of different sizes,and mesh, respectively, with a cluster gear fast to a main feed clutchhead 8'! rotatably mounted on the output speed shaft '11. The clustergear comprises three gear members 88, 89 and 90 which are in constantmesh with gears 82, 84 and 85, respectively. Also, each of saidcountershafts 18, T9 and 80 has a sliding clutch part or cone 9|, 52 and93, respectively, splined thereon for reciprocating into and out ofengagement with the clutch heads on said countershafts.

The output shaft 11 has a quick return clutch head 94 rotatably mountedthereon and carrying with it a mating gear 95. The clutch head 94 is inopposed cooperative relation with the main feed clutch head 31' so as tobe served by the clutch slide or cone 96 splined on the shaft 11,whereby one of the clutch heads 87 or 94 will be engaged when the otheris disengaged or both disengaged when the cone is in a neutral position.The quick return clutch head 54 is for connecting the shaft T! with themotor I00 for effecting quick idle motions of the tool slides 23, 25 and26 and, to this end, its mating gear 95 is driven from the motor I00.

The counter-shafts 18,19. and 80 are driven from the input shaft 16through hand-change gears (NH-Hi2, It3i04, and lli5ll!6 respectively)splined on the ends of said shafts so that they can be readily removedmanually through a suitable openin in the casing 20 to effect variousratio combinations of speeds between the input shaft 15 and saidcounter-shafts in a manner well known in the art. With the selection ofhand-change gears shown, the fine or first feed counter-shaft 18 of thefeeding mechanism is driven by gears l0! and H32; the second orintermediate feed counter-shaft 19 is driven by gears Hi3 and 1M; andthe third or coarser feed counter-shaft 80 is driven by gears I05 andI06, all, as above stated, are hand-change gears well known in the art.

The three automatic changes of speed of feed of the tool slides areobtained in the following manner:

1. For fine feed of movement of the tool slides and all of the clutchcones 9|, 92 and 53 being out of engagement with their respective clutchheads, the clutch cone 9! is moved into clutching engagement with theclutch head 8| and cone 96 is moved into engagement with main feedclutch head 81, thus the drive being from input shaft 16 throughhand-change gears Nil, 502, shaft 18, clutch head 8|, gears 82, 88, andmain feed clutch head 81 to output shaft 11. It may be noted here thatthe clutch cone 55 is in en' .zaagement withfthemainifeedzciutchheadB1duringzalljfeedingoperations.and is onlymoved out of engagementtherewith when it is desired to eflectithe quick idle movements of thetool slides or'whenithe feed mechanism is hand'operated for setting-up:or the machine stopped;

.E'or the second or intermediate feed of the tooltslidesand-cones 9i:and 53 being disengaged fromitheirrrespective .clutchheads, the cone 22lS.I2'lOV8d :in engagement with clutch head 83, "thus the drive-beingfrom input speed shaft 15, through hand-change gears I03, Hit, shaft'19, clutch head 83,.gears 8'4, .89, and main feed clutch head 3! tooutputzshaft ll; and

:3. Forthe-thirdor coarse feed of tool slides and with the clutch conesl8 and it dis n aged from their respective clutch heads, cone 93 ismoved into engagement with on head 85, thus the .drive being from speedinput shaft 75 through ,hand change gears H35, 2%, shaft '50 clutch head35, gears 8%, 9i), and-main feed clutch 'headfi'i'to output shaft Aswill be seen hereinafter, the ;mechanism which operatesthe clutch cones9%, 92 and 93 is to'be interlocked so that, when any one of the threeclutch cones is operated to engage its clutch head, the automaticallydisengage any other of said clutch cones that was previously inengagement, this being a safety feature which permits only one of thethree feed clutches to be engaged at one time while the other clutchheads and-their'mating gears run idle on their respective shafts. Also,the counter-shafts l8, wand-Bil are rotated continuously from the in-:put shaft '55 through their aforesaid respective hand-change gearswhile the machine .is .in operation. I

The fast motionofzthe tool slides and 25 (that is, their idlemotion fromthe time that any tool "then in operation has finished cutting and isbrought back to clear the subject being machined, the turret indexed,and then moved forward to bring thejnext set of tools to the subject) isobtained hymeans of the fast motion .motor I09 through sprocket chain'51? trained tools of the turret slide 23 and/or the cross slides :25and Nero again in position for cutting operations 0n the work-subject,the quick return clutch 94 is disengaged and the main feed clutch 37isengaged by the cone 9% whereby shaft if is again brought to feedingmotion. When fast motion is in operation, cluster gear '38fi9--9il runsidle on shaft ll and shaft 16 :runs idle in -theiend ofshaftil, as shownat point w From output shaft il, feed or fast motion is transmitted tothe feed shaft 38 (which opcrates turret slide 23 and'cross slides 25and 28) through gear till fast on shaft 17 and meshing with gear 1 Hkeyed on feed shaft 30.

The operations of the machine are automatically controlled by animproved control device, generally indicated, l l2 disposed at andwithin the front portion of thehead stock casing 20, 'see Figs. 1 and 2.This control device is driven by beveled gear H3 fast on shaft 1'! andmeshing with beveled gear H1 keyed on warm shaft on a supporting shaftml.

48 and, through worm H8 also keyed on shaft H3, drives worm gear 528secured to-one end of a dog drum l2! which is freely Ijournaled Thus,the timing between thedog drum [2! and the feed shaft to will not bealtered. The control-device comprises, in part, the dog drum 'I2l (Figs.1,2 and 5) provided on its peripheral surface with a multiplicity ofparallel .circumferentially :extending slots in which may be adjustablyfastened dogs 22 arranged to operate electrical contact switchespositioned on a bar or casing 123 disposed above the dog :drum. Theswitches are arranged in a :row extending longitudinally of theperiphery to the dog drumiand are twelve number for the purposes of themachine-illusn the drawings and are designated .A'to sive. There areeleven circumferential rows of slots 12 Win the dog drum to. serveeleven of those switches-i. e., :switches 13 to :Linclusive. Switch A isprovided as a safety feature for cutting off all automatic power'driven'motion to the tool slide when hand cranking. The switch Iautomatically or manually stops the rotation of the spindle as when itis desired to jog the machine for setting-up purposes. The remainder ofthe switches operate electro-pneumatic valves for shifting clutches (orother speed change mechanism) that change the spindle speed or rotationof the feed or sliding movement of the turret slide and the :crossslides during cutting operation as well as to effect the quick-idleslide movements of the slides or to stop the movement of said slidesentirely except as may be accomplished by'hand cranking of the machine.

The switches B to L are actuated bythe dogs 1222 through the medium ofinterposed levers b to Z respectively there being one of these leversfor each of the switches, and arranged to cooperate with theircorrespondingly designated switches in upper case characters. Theselevers extend transversely of the dog drum and are rotatably mounted ona shaft I24 'journaled in the brackets i25. The rear ends I26 of thelevers (Fig. 2) project beyond the shaft I24 to engage the back of theswitch bar i23 which acts as a stop, and the forward portion of thelevers are heavier and extend at least to an elongated hand-hole 12!(Fig. 1) in the forward wall of the head stock 29, where they may bemanually engaged to be lifted up from normal position for operating anyone of the switches 12 to i. For purposes of convenience the levers f, gand 2. protrude beyond'the hand-hole I21. The lower edge of each ofthese levers. 'b "to l inclusive, is provided with a depending lug Z andpositioned to lie in the path of 'a dog (22 applied to the drum to liftsaid levers, respectively, so that the adjustable contacting head (28will engage the spring loaded plunger Y of their respective switches.

As shown in. Figures 1, 2 and 5,"the worm shaft H8 is provided on itsouter extremity with a square end i I 8 to receive a hand-crank, orother implement, for hand-cranking the machine for setting-up purposesas is well understood in the art. When hand-cranking, it is desirable asa safety measure that the fast motion motor I39 be lie-energized. Theswitch A is 'a'slide stop motion or cut-out switch for all automaticoperations of the tool slides and has-itsspringloaded plunger arrangedto be 'engaged'by the adjustable contacting head 123 of the lever-arm afast on the shaft I24 to depress said plunger decades 9 against itsbias. The end of the shaft I24 adjacent shaft IIB has fast thereon alever-arm I29 which has its free end portion I29 lying normally in aposition to obstruct the insertion or application of a tool or implementto the square end iII8 for effecting hand-cranking unless the free endof the lever-arm I29 is manually lifted, which rotates shaft about itsaxis and lifts leverarm a to depress the plunger of switch A to operatesaid switch.

Tool slides As above stated, all movements of the main or turret slide23 and of the cross-slides 25 and 26 are actuated from a single disc-camI35 driven from the feed shaft 30 having worm I48 fast thereon andmeshing with worm gear II fast on the arbor I54 of said disc-cam, whichlatter also unlocks the turret, indexes the turret I65, if one isemployed, actuates a cross-slide preselector device S that renderseffective and ineffective the connection for operating the crossslides25 and 26 from the movement of the main or turret-slide 23 (see Figures1, 4, 6 and 7), all as more particularly shown and described in thecopending application above mentioned.

The present invention, however, embodies the improvements, over thedisclosures in the aforesaid copending application, namely (1) forposi-- tively forcing the turret lock-bolt I75 back to locking positionto effect an accurate indexed position of turret and positive bindinglooking or clamping of the turret in indexed position, which has amarked effect on the accuracy of the work produced by the machine; and(2) a slide-tool operating device-all actuated from the same disc-camI35 in addition to its other function as mentioned in the precedingparagraph.

The main or turret slide 23 is of a hollow flat box-like formation witha relatively wide central longitudinal slot 23 on its bottom side. Themarginal edge portions of the slot 22 are oifset to form channelsslidably resting upon track-ways I36 and I37 upon which the slide 23 isreciprocated to and fro with respect to the chuck 22 by the horizontallydisposed disccam I35 positioned within the slide 23 and above the waysI36 and I37. The cam I35 is provided with a substantially heart-shapedbox-cam groove I35 on its upper surface and a cam roll or follower I47,carried on the under face of the top wall of the slide 23, extends intosaid cam groove I35 the cam I35 rotating in the direction of the arrowshown in Figure 7.

The disc-cam I35 makes one revolution for each full reciprocatorymovement of the slide 23- i. e., from its rear starting point (when theturret IE5 is indexed) forward toward the chuck 22 and back to itsstarting point. The slide 23 is shown in Figures 1, 6 and 7 in its rearor starting point position and just after the turret has been indexedand locked into position by the wedge-lock-bolt I75.

The turret I65 has vertically disposed polygonal tool-carrying faces andhas a depending hub I72 rotatably mounted about a vertical axis in theforward end of the main slide 23, the tool-carrying faces extendingabove the slide 23to oppose the chuck 22. Applied to the lower end ofthe hub I72 is an index and lock discplate I74, in the form of anannulus, secured by bolts I74 The under surface of the discplate I74 isprovided with a plurality of grooves I76, one for each face of theturret and arranged in a somewhat radially offset, as indicated bydotted lines in Figure '7, to. receive an indexing pin I on the disc-camI35after the manner of a Geneva movement-for indexing the turret. Theupper surface of the disc-plate I74 is reduced in diameter to provide acircular groove I78 underlying the hub I72 and with the perimetralsurfaces of the reduced portion formed polygonally, as at I79, tocorrespond with the number of and the position of the turret faces. Thepolygonal surfaces I79 are upwardly and inwardly inclinde to be engagedby a corresponding surface on the wedge-lock-bolt I75.

The wedge-lock-bolt I75 is supported in a horizontally slotted orbifurcated front face I8I of the guide-block I63 with the bottom wall orcrotch of the slot oblique, as indicated in Fig. 7 of the drawings, toprovide a wedge slot so that the wedge-bolt I75 slides into: such slotlongitudinally thereof and transversely of the machine and under theaction of a biasing spring I 95 to locking position its straightchamberedforward edge will bear against the complemental chamferedsurface I79 on the disc-plate I74, the opposite edge of wedge-bolt I 75being formed complemental to the bottom wall of the wedge s10 I8I.

At a point in the rearward return movement of slide 23 and before itreaches its rearmost position, the disc-cam I35 moves plate-cam I82,mounted on its upper surface, into engagement with roller I33 carried bylever I84 to swing the lever I84 counter-clockwise with respect toFigure 7, thus withdrawing the wedge-lock-bolt I75 against the tensionof the spring I90 to release the turret I55 for indexing. The one endfulcrumed at I to a rear portion of the slide and its other end formedwith a radius extremity I37 extending into a correspondingllywforwardslot I38 at one end of the back bolt When the bolt has been so withdrawnthe indexing pin I85 one of the indexing grooves I76, which groove hasbeen brought to position to receive the indexing pin I80 by a previousindexing of the turret. Having entered the groove and continued in itsmovement with cam-disc I35, the pin I80 has indexed the turret I55 oneposition or face and is shown in Fig. 7 as now leaving said groove.

During this indexing of the turret I65, the cut-out portions I89 of theguide block I63 and the cut-out portion I89 of the wedge-lock-boltreceived complemental portions of said lockbolt and guide block,respectively, thus providing sufficient clearance to allow indexing ofsaid turret.

After the indexing pin completed the indexing of the turret, the dwellI82 on the plate cam I82 releases the arm I84 to allow the biasingspring I to drawthe wedgelock-bolt I 75 and snap it into the positionshown in Fig. '7 where it wedges itself between the oblique bottomsurface of slot I 8| and the opposing chamfered surfaces I79 on thedisc-plate I74 securedto the bottom of the turret. i

As before stated, an improvement of the present invention over theaforesaid copending application, resides in arrangement of the biasingdevice I90 and in means on the disc-cam I35 for positively wedging thewedge-lock-bolt I75 in its turret locking and binding position afterhaving been preliminarily brought to that position by said biasingdevice I90.

I89 has substantially lever I84 has will have been moved to enter-To'this end and referring to Fig. 7, the spring I90 is disposed withinthe slide 23 along its rear or back side and has one end anchoredthereto by astud I94 while its other end, adjacent the wedge-lock-boltI15, is connected to one end of a bell-crank lever 93 of a compensatingtoggle. The other end of the bell-crank lever I35 is pivoted to thewedge-lock-bolt I15, as at I31, by a link I95. The compensating togglefurther comprises alink: I35 pivotally connected to intermediate elbowportion of the bell crank lever I95 and pivotally supported by a pin orbolt I36 fixed on theunder surface of the top-wall of the slide 23. Thiscompensating toggle, biased by the spring I90, produces a very effectivesnap action on the wedgelo'ck-bolt H5 in returning" it to lock position.Under certain machine operating conditions, theaction of the spring I33alone is inade-'- quate to accomplish both the accurate location andbinding of the turret I93. To overcome this situation the intermediatearm I83 on lever I34 and which carries the cam roller I83, is extendedlaterally across the disc-cam I35 to have its free end lieon the otherside of the axis I53 of said disc-cam [35. This free end of the arm l83=carries a cam roll I83 which is engaged by a lugcam- I83, adjustablysecured to the top surface of the disc-cam I35, after the spring I93 hasreturned the wedge I31 to its turret locating and binding position, andthus exerts a pressure on thelever' I84, which tends toinoveit in aclockwise direction in Fig. '7 and causes its radius extremity I81 toexert a squeezingaction on the wedge-lock-bolt I13 to positively seatthe latter and accurately locate and bind position.

At or about the same time the turret IE5 is indexed, a pin 243 onthedisc-cam I33 entersin one of a plurality of radial indexing grooves239 in the undersurface of an indexible wheel 233 of a cross-slideselector S, which may be rendered effective, according to the manner theselector has been set-up for a particular production operation, any oneor both, or neither, of the cross-- slides and 26-, as is fully shownand described in said Patent No. 2,455,87 6. It will suffice to say thatlatch members 230, controlled by the selector S. engage or disengagekeepers 1' on push-rods 205 which actuate said cross-slides from thetoand fro movement of the turret slide 23. upon'each revolution of theselector S, a lug 345 on the disc 235 oscillates a cranl; 335 of alubrieating pump 346.

After the turret has been indexed and locked and the proper selection ofthe cross-slides has been made',;the slide 23 is actuated by the disccamI with quick or fast motion from motor I33 through clutch 94, shaft 11and shaft 33 toward the chuck 22 until the tools (not shown) on theturret face are about to contact the work-piece (not shown) held by thechuck. At this time a dog I22 on dog drum iZI, acting through meanslater to be described, shifts clutch cone 93 disengaging quick-motionclutch 94 and engaging main feed clutch 81, thus actuating the slide 23of slow cutting feed movement'until that cutting operation has beenperformed. It is, of course, understood that the cycle of operation ofthe machine is governed by the number of faces of the turret I65 or bythe number of such faces as may be employed for any operation upon aworkpiece according to the setup of the machine, for instance, themachine may be equipped with a skip face" mechanism not shown.Consequent- 1y, at the end of eachforwardfceding motion of the turretI35'in a any face of the turret 1recessing onv the workpiece;

- I35 andthe way I37.

12 the turret slide 23, when the slide-follower I4! is in the dwellportion. (ii-v of the cam-groove I35 of disc-cam I35, a verticallymovable slidetcol actuator T is operated, which is mounted on theforward end of the turret slide 23. The mechanism for operating thisactuator T is another improvement of this invention.

A slide-tool actuator T employed on most of the automaticchucking-turret-lathes consistsof a slidably mounted bar having anotched upper end t which interengages with a similar or coinplementalnotch member 13 of the slide-tool device I35 (partially shown in Fig. 6)secured to any selected faceof the turret H35. Therefore, carrying sucha slide tool and when indexed to operative position, the member 3 of theslide-tool will interengage with the endt of the actuatorT. These: slidetools are usually employed forgrooving and internal is imparted to theslide-tool actuatorT by a bar 333 disposed within the slide 23 below thedisc cam I35 and extending longitudinally of the turret slide I23between the axis I53 of said disc-cam The rear end of the bar 438 isreduced and slidably mounted at cm in a bearing formedon theturret-slide23. The forward end of the bar 433 is similarly slidably mounted at 332in a bearing-formed in the turret slide 23 and is provided with a seriesof rackteeth are which mesh with an elongated pinion 333 whose axis isjournalled in bearings on the turret-slide as at 435. The actuator T isalso formed with rack teeth 5% which mesh with pinion 533. (See Figures6 and'l.)

Disposed adjacent the rear end portion of the rod 333 and on the topsurface thereof is a flat elongated abutment plate 40'! pivotedintermediate its length to said bar on a vertically disposed pin 438fast in said bar. The forward end 309 of the latch member 491. may bebeveled, as shown, to be engaged by apin 413 depending from theunderside of the disc-cam I33 to shift the bar all!) rearwardly, whichmotion is transmitted by the pinion 434 to the slidetool actuator T tomove the same vertically and,

thus, actuate the slide-tool. The abutment plate 63! is formed at a rearcorner portion with a depending lug MI which abuts the adjacentside ofthe bar 308 to prevent swinging movement of the abutment plate lfl'iwhen it is engaged by the pin MI] in the manner-just described, theabutment plate 531 being normally biased to the position shown in Fig.'7 by a spring M2 having one end connected with the lug MI and the otherend anchored to the bar 400.

The bar etc is returned to its position shown in Figs. 6 and 7 by a pin#13 projecting from the underside of the disc-cam I35 and which pin willengage the free end of the bell crank lever 4M pivoted at M5 to anextension projecting from the sump wall of the pump 344. The other endof the lever M3 extends between confining shoulder formed by a recess M3in the bar 433. When the free end of the bell crank lever A is contactedby the pin M3, it will rotate the bell crank lever on the pivot M5 in acounterclockwise position and return the bar 430 to its full lineposition shown in Figs. 6 and '7, and thus move the slide-tool actuatorT downwardly to its original or starting position.

When viewing Fig. '7, it may not be readily apparent that the pin 1H3would ever contact the latch member 438 or the pin M3 would evercontact. the lever M4. In thisv connection it Vertical movement must berealized that the axis 153 of the disccam I35 is fixed in relation tothe longitudinal movement of the turret slide 23 which carries the bar488. By referring to Fig. 8 it will be observed that, before the camfollower I41 approaches the dwell in the cam groove I35, pin 3 passes inforward end 489 of the abutment plate 401; but just as cam follower i4?enters the cam dwell at 1; (see Figure 9) the turret slide 23 is then inits position nearest the chuck 22 and pin 4|!) will contact the endsurface 489 of the abutment plate 481 and push the bar 488 rearwardlyfor a distance and for a duration suflicient to effect the operation ofthe slide tool actuator T. By further reference to Fig. 9, it will beobserved that, when the bar 408 has been pushed rearwardly to the limitof its distance by the pin 4"), it will assume a position indicated indotted lines and the free end of the lever 414 will have been swung intothe path of the pin M3 and will be contacted by pin 4l3, after pin 4E0passes by the abutment plate 401, and thus impart a counter-clockwisemotion to the lever 4M and return the bar 408 to its original initialposition.

The abutment plate 491 is pivoted in the manner above described so that,if the machine is hand-cranked backwards that either of the pins M9 orMS come in contact with the forward end of the abutment plate 481, saidabutment plate will swing clockwise on its pivot 488 thereby avertingany jamming which would otherwise occur, the relative movement .of saidpins and of the turret slide I23 being such that the pins would onlystrike the abutment member 401 forward of the pivot pin 488.

Control mechanism From the above, it should be clear, particularly fromFigure 4, that by clutch cones 43 and 44 selectively engaging theirrespective clutch heads 394i) and til-42, four automatic speed changesof the spindle 2| are effected, that by clutch cones 9|, 92, and 93selectively engaging their respective clutch heads 8!, 83 and 85, threeautomatic changes in the feed movement are effected for cuttingoperations of the turret slide 23 and the cross slides 25 and 26 andthat, by clutch cone 96 alternatingly engaging its clutch heads 8'! and94, movements will be transmitted to said slides and the slides will bemoved at their feeding rate or in rapid motion from the quick or rapidmotion motor 180, respectively, or, when the clutch cone 86 is inintermediate or neutral position, all automatic motion is disconnectedfrom the said shaft 38 and the dog drum I2l, and, consequently, from thetool slides 23, 25 and 26. It will be understood that a cycle of themachine embraces an operation where the turret slide 23 has reciprocatedback and forth relative to the spindle a number of times correspondingto the number of faces on the turret N55 or to the number of faces thathave been brought to indexing position for the tools thereon to performwork on a given subject work-piece. The operation of the clutches, justmentioned, is attained by the electro-pneumatic mechanism schematicallyshown in Figures 4 and 15 and more particularly shown in its arrangementand organization in the present machine in Figures 1, 2, 3 and 10 to 15inclusive.

The electropneumatic mechanism, for actuating the speed change and feedchange clutches,.includes air cylinders M1, M8, 428, 429

and 430 disposed in a compartment C at the rear of the headstock 20 andarranged adjacent the clutches which they actuate; and to one side ofthe air cylinder compartment 0' is another compartment 0 in which aredisposed the solenoid air-valves for said cylinders, as shown in Figures2 and 3. An important feature of the present invention is thepositioning of the. air cylinders so that their operating pistons areconnected directly to the yoke which shifts the. clutch cones, therebyeliminating a number ofparts (such as connecting rods, linkage, etc.)

which not only complicate the mechanism but develop lost motion andconsequently affect the spontaneous operation of said clutches. Asshownin Figure 3, air cylinders 4H and .418 are, mounted on a verticalweb or partition 4| 9 with,-

in the head stock 28 and in close proximity to the feed-change clutches3948 and 4l42,

respectively. These air cylinders may be one casting or unit divided bya central partition.

Each cylinder is provided with a stemmed piston 4|! and 418*,respectively, the stems or rods of said pistons being arrangedsubstantially parallel to the axis of said clutches 3948 and, 4l--42.The cylinders 4ll--4I3 are preferably arranged so that their respectivepiston rods extend from them in opposite directions and disposedadjacent the clutch cones 43 and 44, respectively, the ends of thepiston rods being pivotally connected, re-;v spectively, to the rockerarms 420 fast on shafts 42l extending through and suitably journaled' inpartition walls M9, the other end of said shafts having fast thereonrocker arms 423 attached to clutch yokes 424 extending in thecircumferential groove in their respective clutch cones 43 and 44. Oneach lever 42!] is a pro jecting lug 425 which moves between adjustableabutments 428 and 421 so that the movement of the clutch cone may benicely adjusted.

Both cylinders 4H and 4!!! are connected with an air pressure source attheir opposite ends so as to render the pistons therein double-acting-that is power operated in both directions. Thus, one end of thecylinder 4" is connected by the air line B to the solenoid air valve Bso that the piston 4|! may be moved to operate the cone 43 to engage theclutch 39 and disengage said cone from the clutch 46, while the otherend of the cylinder 4|! is connected by an air line C to solenoid airvalve 0 so that the piston 4l'i may be moved to operate the cone 43 toengage clutch 40 and disengage clutch 39 (see Figure 4). Cylinder M8 isconnected by air line D to solenoid air valve D to move piston 8 tooperate cone 44 to engage clutch 4| and disengage clutch 42, while theother end of cylinder M8 is connected by air line E to solenoid airvalve E to move its piston 4I8 -to operate clutch cone 44 to engageclutch 42 and to disengage clutch 4| (see Figure 4). The solenoids ofthese air valves B, C", D, and E are energized respectively by thesingle-pole snapswitches B, C, D, and E which are closed by appropriatedogs I22 adjustably mounted, as required fora desired operation ofmachine, on the dog drum l2! to effect the four speed-changes ;v whichhave been described above.

As can be seen from Figure 4 and the disposition of the shafts in Figure2, the gears 82, 84 and 86, which are driven by the clutches 8!, 83 rand 85 respectively, are grouped about the cluster gear (88-49-98) fastwith the main feed clutch 81. The feed gears 82; 84 and 86 and therespective clutches 8|, 83 and 8 5 are'shown iirFigure. 3. together.with their clutch;

con qal 92. and 93 (although, ior'thepurpose; of" clarity.- the. mainfeed clutch 8.7, and its;

cluster.- gear is not shown.in:Figure,.3.).. The, clutch conesx.9l,..92and 93 are actuated tov engage, their clutches byair, actuatedpistons..4-28. 42 and.

430 mounted,. respectively, in. air cylinders, 4 28; 42.9. and: 43Bpivotallymounted at, one. of; their ends, at..43.| to: an: end. wall.of. the, head. tQQk. casing: 20 so as; to permit. slight movement. of.

the cylinders to: compensate. for operational movements of.theirxpistons. The rods, of. piston.-

428; 42-9 and 436s extend from the. other end of. their" cylindersand.;.in.the. same; general di rection'as..the.zshafts.18, lilandtllupon which the: clutch cones 9|, 92.. and. 93 are spiinedandeach:pistonrod.isoperatively. connectedwith. one

of said cones,,respectively.. Saidconnections, be-- being 'connectedtorocker armsi'432, 433. and 434,

respectively, which. are fast on one. end portion of" shafts 428 429.and 4am, respectively, and,

the: other end of saidshaftsbeing disposed: adjacenttheinclutch cones9|, $2 or 93. and having fast thereon arccker. arm 432 ,1333 and 434%which: carries a yoke 9H,. 92 andtteeach extending into a customarycircumferentialgroove; in" their; clutch cone-5.. Said shafts. 428 4219and 43t are journaled. in. the. vertical partition wall4l9.

Feed-change cylinders428, 429 and 436 are; each connected by air'pipelines.J K and L -to their respectivesolenoid air valves J ,;K' and L soas to be single-acting under air pressure. for: en.- gaging" theirrespective clutches 81;, 83 and 85 when. air: is introduced into: saidcylinders. As shown in Figure 3, the piston 4303 has been, air actuatedto engage clutch cone 53 with theclutch 85- and, when air is releasedfrom th cylinder 430 bythe exhausting of its solenoid. air valve L'-',the clutch cone remains engaged with the clutch85'. When one of-saidclutches 8i, 83 and 85 are so engaged, the other of said clutches'are.

disengaged by a verysimple and novel arrangement of three levers 435,431 and 438,,and which.

arrangement is permitted by the air cylinders 428; 429 and 43B and theirrespective pistons being--disposedin spaced side-by-side position and.

in'substantiallythe same plane, as shown in Figures 3 and 4. To thisend, the rods ofpistons.

tonrods 428 and 829. and has its ends inthe plane of movement of saidshoulders 42% and 429t0 be contacted by'the latter. A similar teeter.lever 431 has its ends similarly disposed between shoulders 429 and 439?and pistons 529. andv 43.0 A third teeter 433 is similarly mounted asthe other two but extends between the piston rods 428 and 430 and hasits ends in the path of movement of abutting contact shoulders 423. and430. Thus, it will beseen that if air is admit-- ted to any one ofcylinders 428 429 or 439, the pistons of the other two cylinders will bemoved to the right, in Figure 3, and fully disconnect the clutchesassociated therewithprovided, the air pressure has been exhausted fromsaid latter two cylinders. It will be obvious that this arrangement oflevers 436, 431 and 438 also serves as a mechanical interlock andassures against more-than one clutch 8!, 83 or 85. being engaged ny Onetime. Th sbl noi s f e e ee changea r va v srJfi. s a daL' ara ne s dre,- spectively bythe single-pole sna -switches J,

and L which, are closedby appropriate dogs I22 adjustablymounted on thedog drum I21 to ef fectthedesired changes in the feed movementof.

the turret slide 23 and cross slides; 25 and 2G.

The; solenoid air valves B, C, D, E, F J',

K" and L are. of a well-known, standard threeway; type that. pass. airpressure therethrough when. the solenoid is energized and when.deenergized cuts off the passage of air-'therethrcugh from thesupplysource andexhausts the air; pressure, onits outlet side. One. type ofsuch valve that is. now employed comprises an elongated casing havingan; opening in itslower end which isthreaded on a main air pressuresupply line.

439-having-;:apressure regulator 44 9, 0f' any well known type, therein.(Figures 2 and 4. so as to 1 normalize; the, air. pressure flowing tothevalves againstviolent fluctuations occurring inthe air pressure;system..Also, a pressure switch 44 0 is.

connected in the air supply line 439 and fume tions asa safety cut-out,device bycontrolling anelectric circuit, 416 4'i6 that-stops motors Mand 1.0.6. to render the machine inoperative when the airpressurefallsbelow a safeoperating pressure for actuating. theclutches of themachine.

The interior of. the valve casing. 44! (Fig. 10) is divided.transversely by a partition having a boretherein longitudinally of saidcasing. The bore has an inlet-port 442. and a lateral outlet port 442'to whichpipe connections may be made,

and the ends of the. here are provided with seats 443 and 444. A rod445, of muchless diameter than the bore, extends looselythrough saidbore and has a valve 446 on its upper end to cooperate with the seat443-and has its other end extending beyond the. seat 444 when valve 446is on its seat 443. A valve. 44'! is slidably disposed in the lowercasing chamber to cooperate with its seat 444 and isnormally springbiased to. seating position to. cut off. air pressure from the supplyline. 439.; and, in this position engages and lifts therod 445 to unseatthe valve 446, thuscommunicating the outlet port 44%. with an exhaust.

port 448 positioned in the valve casing 44! beyond the seat 443 and,thereby, exhausting the airv pressure from they aforesaid air cylinderto which the valve casing is connected. A solenoid 449 is mounted on topof thevalve casing 44 l. and,

when energized, its, armature-4,49 depresses the rod 445 to seat valve446.0n its seat 443 (thus cutting-off the communication betweenexhaustport 448 and outlet port, 442 and, at the same time,

thelower endof the rod 445 is projected. beyond the. seat 444 and,thereby, unseats valve 441 against its biasthus allowing air pressure toflow from supply pipe 439, past seat. 444 and through outlet port 442until the solenoid 449 is de. en-

ergized when the; spring 450 moves the armature. to raised positionallowing the valve 441 to be.

seated which pushes rod 445 to unseat valve 448 and open outlet port 442to exhaust 448.

The clutch cone 98, asbeforedescribed, serves both the; main feedclutch. 81 and the fast-motion clutch 94, more; clearly'shown in Figures1 and 4., and. is. moved to its two clutching positions and. to itsneutral position by a plungermechanism P that is actuated by airpressure to engage fast-motion clutch 94' and to disengage main feedclutch 81 or to neutral position and that is actuated by spring biasingmeans to engage the main feed clutch 81 and disengage the fast-motionclutch 94. This plunger mechanism is shown in detail in Figures 11 to13, inclusive, and is indicated in Figures 1 and 2 as disposed in aboutthe center of the headstock casing 20 behind the dog drum [2L Theplunger mechanism P comprises a cylinder 45! having slidable therein aplunger 452. Projecting from one end of the plunger and through the endwall of the cylinder is a stem 453 which has its free end portion insuccessive steps to form two circumferential shoulders 454 and 455 eachof progressively reduced radii toward the extremity of the stem. A rod456 slidably extends through an opening in the other end wall of thecylinder 25l and through an axial bore 45? passing through the plungerand its stem and is threadedly connected with said stem at the free endof the latter and by a lockwasher and nut. The bore 45'! is of greaterdiameter than said rod 455 (except at the threaded connection of the rodwith the stem) to accommodate a helical compression spring 458 that hasone end bearing on a shoulder formed by the bore at point of connectionwith said rod and has its other end bearing against a shoulder, formedby a recess 45! as an extension of said bore, provided in the end Wallof the cylinder opposite the stem 453 (Figure 12). The rod 456 has itsother end extending into a bifurcated portion of the distal end of asupporting lever 459 pivoted on a stub shaft 454 to oscillate thereon(Figures 1 and 11). The distal end of lever 459 has a transverse boretherein bisecting said bifurcation and through which a pin 46! extendsto pivotally connect said rod 453 to said lever. A clutch yoke 55*- hasits shank inserted into the end of bore in said lever 45% and its yokeportion embracing the clutch cone 95 and lying within the customarycircumferential groove in said cone. Thus, it will be clear that theposition of the plunger 452 determines the position of clutch cone 96and, consequently, the engagement or disengagement of the clutches 8iand 94 and, also, that the force of compression spring 458 against theplunger is in the direction required to engage the cone 55 with the mainfeed clutch 81, which gives the plunger 452 the position shown inFigures 4 and 12.

Laterally extending from the end plate of the cylinder 45! through whichits plunger stem 253 projects, is a bracket 463 which supports a latchbolt 454 slidably mounted in a bore or passage in a boss or enlargementon the bracket for movement at substantially right angles to the stem453 and whose detent end is positioned to engage and cooperate with thestepped-end portion of said stem. The latch 464 is suitably biased, suchas by springs 465, to have its detent end normally contact and ride uponsaid three stepped surfaces at the end portion of the stem 453 and to bewithdrawn, against its bias, out of complete contact with (or out of theplane of movement of) said stem by a solenoid H mounted on the bracket463 and connected with said latch. The boss or enlargement, in whichsaid latch is mounted, is provided with an air passage 466 that isbisected by the latch 464 and has one end leading into the cylinder 45!at 465 on the stem-side of the plunger 452 and its other end exhaustingto the atmosphere as at 466*. The air supply line 439 is connected withthe air passage 455 between its connection 466 with said cylinder 45!and the latch 464. The latch 464 is formed with a reduced portion orport 461 so positioned thereon that when the solenoid H withdraws thelatch as shown in full lines in Figure 12, said port 46'! aligns withthe passage 466 to release any air pressure within the cylinder 45! tothe atmosphere through port 466 The purpose of exhausing the cylinder45l at this point and time is to eliminate any dash-protection ofplunger 452 and to rapidly exhaust all air pressure that may be presentdue to the valve F not exhausting with sufficient celerity when itsoperation is immediately followed by the operation of the feed-switch Hor when' the fastmotion lever f is being held in lifted position by handwhen feed-switch H is being operated by dogs on the dog-drum I 2|. Whenthe solenoid H is de-energized, the springs 465 shift the latch and thearmature of the solenoid to the full line position shown in Figure 12,where the port 461 in the latch is moved out of alignment with the airpassage 466 thus closing the exhaust port 456 and end of the latch againengages and rides upon the stepped end portion of plunger stem 453. Themoving parts of the plunger mechanism P are, as at present constructed,ground-and-lap fitted with their complemental stationary parts, wherenecessary.

The air pressure introduced into the cylinder 45! at 456 is controlledby solenoid air valve F-in the supply line 439 and energized by thedouble-throw-fast-motion switch F, that is manually biased againstoperation by a suitable placed dog E22 of the dog drum [2 lto force theplunger 452 in the direction required to compress spring 458 and toengage the clutch cone with fastmotion clutch 94. As the plunger 452reaches the half-way position in its movement from feed position tofast-motion position (Figure 12), the latch 464, biased to normallyengage the stepped end portion of the stem 453, engages the firstreduced portion of said stem forming shoulder 454 and, if solenoid airvalve F is de-energized at this time, said latch will be engaged byshoulder 454, thus preventing compression spring 453 from returningplunger 452 to its feed position v (shown in full lines Figure 12) andretaining the clutch cone 96 in its neutral position thus stopping allautomatic or power driven movement of the turret slide 23 andcross-slides 25 and 26.

However, should the solenoid air valve F remain energized, the plunger452 will continue to its fast-motion position and shift clutch cone 95into engagement with the fast-motion clutch 94, at which point in theplunger travel the latch 454 will engage the last step on the plungerstem 453, and consequently its shoulder 455, and hold the plunger, andthus the clutch cone 95, in fast motion position. Air pressure now iscut-off from cylinder 25! by the operation of solenoid air valve F andthe opening of its exhaust port 448.

When it is desired to change the movement of the turret slide 23 fromfast-motion to feed motion, a dog I22 suitably placed on the dogdrum 23will actuate double-throw switch H to energize solenoid H whichwithdraws latch 464 from latched position, whereupon the port 487 inlatch 454 registerswith passage 456 permitting rapid exhausting of airfrom the stem side of cylinder 456 through exhaust port 45G so that thecompression spring 453 will quickly force the plunger 452 to its feedposition as shown in full lines of Figure 12. In the operation of turretlathes, it has been found with plunger mechanism P that the uniform fastoperation of a spring 458, or its equivalent, is desirable to pro viderepeated accuracy in timing, when changing from fast-motion of theturret slide to its feed motion; whereas the slight variations due tochanging air pressure, when changing from feed motion to fast motion istolerable.

Also secured to the plunger cylinder 55% is a bracket 468 locatedadjacent the stepped end portion of the plunger stem 453. This bracketcarries normally open single-pole single-throw switches 69 and asingle-pole double-throw switch 419 suitably arranged so that theirspringloaded button portions may be operated, respectively, by bellcrank levers ll! and 472, intermediately pivoted on a pivot pin M3 to t-e bracket 468. One end of each bell crank lever 41! and 412 engages,respectively, the button ends of switches 46%) and till and is normallybiased in that engagement by springs A74 disposed under said ends of thelevers and seated in recesses formed in the bracket 468. The other endsof said bell crank levels have adjustable abutment screws 459 and Allithreaded therein to contact a lever M5 which has one end pivotallymounted on said pin H3 and its other end in contact with the shoulder455 on the plunger stem sea. The springs Md act also to maintain thescrew abutments 465 and 57% in contact with the lever lie. The screwabutment 468 is so adjusted as to operate switch 459 against its bias toclose it just after the plunger #53 leaves its feed position and againto open said switch just as said feed position is reached; and switch432 is operated against its bias to close one circuit and open anotherjust before the plunger reaches its neutral position when moving fromfeed position to fast-motion position and again is allowed to close thelatter circuit and open the former, under its bias, just after saidplunger leaves its neutral position, when moving from its fastmotionposition to its feed position. These switches 369 and All? are employedfor conditioning control circuits according to the position of theplunger 253 in order to stop movements of the turret slide.

The operation of the combined turret lathe herein shown and described iscontrolled by the electrical circuits shown diagrammatically in Figure15, it being understood that such cross the line diagrams are clear toone familiar with the art; and for the purpose of clarification, thecircuits are marginally bracketed according to the function theyperform. Also, for clarification, the various interlocks or switchesoperated by control relays are designated by the relay number followedby hyphenated sub-numbers. From the reading of the foregoingdescription, it will also be clear that the switches BL, inclusive, maybe operated automatically from the dog drum lZi or manually by thehand-operated levers b to l inclusive, while the switch A is manuallyoperated, only when the machine is to be handcranked; and the start,stop and job button switches 485, 488 and 489,. on the front of thehead-stock 20, are also hand-operated. The plugging switch M of the maindrive or spindle motor M is automatically actuated from the rotation ofthe motor in the usual manner of plugging switches as is common in theart. The air pressure switch 440 is automatically operated by thepressure of the air in the supply air line 539 and the circuitconditioning switches 469 and 413 are automatically operated by theplunger mechanism P.

In Figure 15 the main or spindle motor M, the fast motion motor H30, thecoolant motor and the solenoid H are connected to a main power line 316.A spindle motor M is of the reversible type and equipped with aconventional plugging switch generally indicated at M. Theforwardrotation of the spindle motor M is controlled by relay 2?? that operatesswitch TIl and thereverse rotationof the motor M is controlled by relay3'58 that operates switch l'i8-i. The coolant motor is employed on mostmachine tools for circulating a cooling fluid to the work piece andtools doing the cutting operations and, therefore, form no part of thisinvention. The coolant motor, when a coolant is employed, is controlledby the relay H3 which actuates the starter-switch ll9l of that motor.However, whether the coolant motor is employed or not, the relay H3 isemployed in the con rol circuit for the purpose as will be presentlyseen. The fast-motion motor ice is controlled by the fastmotion relay#289 which operates the starterswitch ied-l of that motor. The otherrelays, interlocks, switches, solenoids employed in the control circuitare all illustrated in Figure 15 and their function will be describednow.

The control circuit is represented by the supply lines Alfi 37t t ispreferred to have the voltage of the control circuit constant andcomparatively low (with respect to the voltage in the main line are) toavoid accident to personnel. Therefore, a transformer 416 is interposedbetween the main line are and the control circuit Wil -41 3 Whilecontrol relays All, illi, 4 19 and 38B are shown in the upper portion ofFigure 15 in association with their respective operating switches orinterlocks, they are also duplicated in their respective controlcircuits at other places shown in the diagram and opposite the marginallegend bracketed portions of the diagram in order that a clearunderstanding of the circuit hock-ups may be had. These control relays,as well as others that are employedi. e., 48!, e32, 483, $84 and wt-whenenergized or de-energized, opens or closes one or more switches whichare called interlocks and will be identified by the number of the relayoperating it, followed by a sub-numeral identifying that particularswitch or interlock.

Thus, with particular reference to the Spindle Motor and the Fast MotionMotor control circuits, as indicated by the marginal brackets in Figure15, it is to be assumed that the machine is completely stopped. To startthe machine, normally open start push-button 485 (also shown in Figurel) is pressed to close the circuit across the line d'i5 ll6 and, sincerelay 41B is not energized, its normally closed interlock being closed,relay 1m will be energized closing forward motion switch t'll-l of thespindle motor M. At the same time, the pressing of the start button 385energizes solenoid 486 which releases latch 48? in the, spindle motorplugging switch M, thus rendering the plugging switch free to beoperated. The energizing of relay 41-! opens normally closed interlock417-2 which prevents spindle reversing relay 478 frombecoming energized,when plugging switch M is closed, due to the rotation of the spindlemotor M which has just been started, and, therefore, interlock 4' |8--2in the circuit of relay 61! remains closed. However, relay 579, alsohaving been energized by the pressing of start button 485, clojses,interlock 419-2, energizing fast motion relay 480, as hand crank switchA is bridging its contacts aa which closes the switch 430I of the fastmotion motor I38. By energizing the fast motion relay 388, its normallyopen interlock 4 -4 is closed to form a holdingcircuit for itself acrossthe control line 476 416 including the normal.-

21 ly closed machine stop push-button 488, thus maintaining relay 480energized as well as relays 471, 419 and 485. In this condition of thecircuits the spindle motor M and fast motion motor Hi9 are running, aswell as coolant motor if one is employed.

As the various switches and interlocks, shown in the"fast-motion-neutral-feed bracket of the diagram Figure 15, are shown intheir feed motion position, it will be assumed that the turret slide 23is now in its feed motion, that the fast motion motor IDS is running andthat the plunger 452 (Fig. 12) is in its feed position as shown in fulllines and the clutch cone 96 is engaging main feed clutch 81 anddisconnected from fast-motion clutch 94. With the plunger 452 in thisposition, the conditioning switches 469 and 410 are in the positionshown in Figure 15, and it is further to be assumed that there are nodogs I22 on the dog drum I2I operating the fast-motion switch F,stop-feed switch G or feed switch H and that these switches are in theposition shown in Fig. 15. With the switches in those positions, controlrelay 484 will be energized from the control line US -41G through thenormally closed contacts f-f of the fast-motion switch F and thenormally closed interlock 482-2, resulting in energizing relay 484closing its holding interlock 484-I and also closing interlock 484-2 inthe line with air control valve F.

Now, to change the movement of the turretslide 23 from feed-motion tofast motion, either by a dog on the drum I2I or by manually liftinglever 1, switch F will open its contacts f'-] and close its contactsf'-f which energizes solenoid air valve F (interlock 484-2 being closedas just stated) thus causing air pressure to pass through solenoid airvalve F into cylinder 45! to move plunger 452 to its fast motionposition, as has been described. Movement of the plunger 452 firstcauses switch 469 to be operated closing contacts y-y and, as theplunger 452 approaches its mid-way or neutral position, switch m isoperated opening contacts :r'w and closing contacts x-:c and neither ofthese changes affects the circuit energizing solenoid air valve Fbecause the switch F will be held to close contacts f'-f long enough forthe plunger 452 to reach its fast-motion position and to be locked inthat position by latch 464 engaging shoulder 455, otherwise the plunger452 will be forced back by its compression spring 458 to neutralposition or feed position depending on where the plunger IS in itscylinder 45I when the switch F is operated to open contacts f';f

When switch 469 was operated closin contacts y -y control relay 48I wasenergized through contacts h -h of feed-switch H, which relay thusclosed its holding interlock 48 I-I as well as interlocks 48I-2 and48I-3 which latter energized relay 483 through closed contacts 9 -9 offeed-stop-switch G; and relay 483, now being energized, closed itsholding interlock 483-I as well as interlock 483-2 but, althoughcontacts ca -m of switch 410 is now closed, relay 482 is not energizedbecause contacts 9 -9 of feedstop-switch G are open. Thus, it is clearthat these changes, just mentioned, in switches 469 and 410 onlycondition other circuits for operation in the event a difierentoperation of the machine is desired.

From what has just been described, the turret slide 23 is now infast-motion and we will assume that it is traveling back or recedingfrom the chuck 22 to its rearmost position, where the turret I65 isindexed and locked, from whence it is again moving forward, underfast-motion, to the workpiece (not shown) in the chuck 22. When thetools are less than an inch (or thereabouts) from the workpiece, thefeed-switch H will be actuated, either by a dog I22 on the dogdrum I2Ior by manual operation of lever 11. (Fig. 5), to open its contacts h -hand close contacts h -h and whether the fast-motion-switch F has beenreleased or not, said feed-switch H will energize relay 482 throughinterlock 48I-2 which is now closed due to relay 48I being heldenergized by its holding interlock 48I-I and switch 459 having closedcontacts 21 -11 Energizing relay 482 opened normally closed interlock482-2, thus de-energizing relay 484 which, in turn, opened interlock484-2 which de-energized solenoid air valve F thus cutting-01f airpressure to plunger cylinder 45I and opening said cylinder to theexhaust port 448 in said valve, despite the fact that fast-motion switchF may be still bridging contacts f Also, the energizing of relay 482closed its holding interlock 482-I and further closed interlock 482-3which latter energized plunger-latch solenoid H from power lines 416.Solenoid H being so energized, latch 464 is withdrawn from the plane ofmovement of the plunger-stem 453 and moves its port 461 in register withexhaust port 466*, hence compression springs 458 rapidly forces theplunger 452 to its feed position (full line in Fig. 12) thus disengagingclutch cone 96 from fast-motion clutch 94 and engaging it with main feedclutch 81, even though full air pressure may be applied to plunger atthe time feed switch H is operated as previously explained; at whichtime a dog I22 on dog-drum I2I will have already actuated one of thefeed-change switches J, K or L for the proper or desired feed movementof the turret slide 23in Figures 3, 4 and 15 the coarse feed switch Lbeing shown as having been selected.

As the plunger 452 moves from its fast-motion position to its feedposition, just described, the lever 4'I5, bearing on the shoulder 454 ofthe plunger-stem 453, is actuated by this movement of said plunger tofirst operate the switch 410 to open its contacts re -x and close itscontacts cp -m connected in the circuit of solenoid air valve F andthen, during this same movement of said plunger and just as it reachesits feed position, said lever 475 operates switch 469 to open itscontacts 111 -11 which de-energizes relay 48I', thus opening its holdinginterlock 48I-I and opening interlock 48I-2, which latter de-energizesrelay 482 thus opening its holding interlock 482-I as well as interlock482-3 which cuts on current to plunger-latch solenoid H and allowssprings 465 (Figures 11 and 12) to pull and yieldably hold latch 454into contact with the plunger stem 453 as shown in full line of FigureI2. The movement of the latch 4B4 closes exhaust port 465 so that airpressure may be again e'ifectively applied to the plunger 452.

When relay 482 was de-energized, as just stated, normally closedinterlock 482-2 was reclosed, thus allowing relay 484 to be energized byfast-motion switch F, if it has been released, so that the turret-slide23 may be taken out of feed or cutting movement and returned to itsrearmost position (for turret indexing) by fast motion. Assuming thatfast-motion switch F has been released and has closed its contacts f -jthe relay 484 is then energized closing its holding interlock 484-I andclosing interlock 484-2 thus allowing solenoid air valve F to beenergized,

